fi 7 '2 PROCEEDINGS OF THE NATIONAL MUSEUM. 



CHERAPS PREISSII Erichson. 



Astacus (Cheraps) preissii Erichson*, Arch. f. Naturgesch., 12ter Jahrg., I, p. 



101, J846. 

 '! Asiaco'idcs plebejus Hess, Arch. f. Naturgesch., 31ter Jahrg., I, p. 164, pi. vu, fig. 



17, 1865. 

 Astacus preissii von Martens, Monatsber. Akad. Wissensch. Berlin, 1868, ij. 617 



(after Erichson). 

 Astacopsis preissii Haswei/l, Cat. Australian Stalk and Sessile-eyed Crust., p. 



177, 1882 (after von Martens). 



Southwestern Australia (Erichson). Erichson's types could not be 

 found in the Berlin Zoological Museum by Doctor von Martens in 1868. 

 Victoria, Australia (No. 435G, Coll. Mus. Comp. Zool., one male). 



The specimen in the Museum of Comparative Zoology agrees well 

 with Erichson's diagnosis, so far as it goes. It shows alow postorbital 

 ridge on each side of the gastric area, terminating anteriorly in a 

 minute blunt tubercle. The rostrum is flat and punctate, lightly margi- 

 n ate, the margins passing anteriorly into the sbort, triangular acumen 

 without developing lateral spines or teeth. The areola is much broader 

 than in G. bicarinatus, measuring 5.5 mm. in width (length of the whole 

 animal, 109 mm.). The outer part of the upper surface of the hand is 

 thickly sown with very large, deep pits. The fingers are strongly 

 curved, the movable one armed within with a large, blunt tooth. The 

 carpus bears a long and stout tubercle on its inner border; this tuber- 

 cle is curved forward and is blunt at the end; there are, besides, a few 

 low tubercles on the anterior border of the lower face of the carpus. 

 The anterior process of the epistoma is bounded behind by a slight 

 transverse furrow; its sides are very convex, and its anterior angle is 

 produced so as to form a thin, vertical plate. 



Hess's Astaco'ides plebejus came from Sydney, New South Wales. 

 The shape of the large chelae, the breadth of the areola, and the color (yel- 

 lowish, the large claws dusky) make it probable that this specimen was 

 Cheraps preissii. The specimen (dry) of G. preissii in the Museum of 

 Comparative Zoology has chelipeds of a very dark purplish color, in 

 striking contrast with the yellow hue of the rest of the body. It is true 

 that the deep, large pits seen on the chelae of G. preissii are ignored in 

 both the description and the figure of Astaco'ides plebejus, and that the 

 telson has a very different shape, if Hess's figure be correctly drawn. 

 Ortmann treats Astaco'ides plebejus as a synonym of Gheraps preissii, 

 but I think that Ortmann's specimen of G. preissii was in reality G. 

 bicarinatus. (See below.) 



CHERAPS BICARINATUS (Gray). 



Astacus bicarinatus Gray, Eyre's Journals of Expeditions of Discovery into 

 Central Australia, I, p. 410, pi. in, fig. 2, 1845; List Crust. Brit. Mus., p. 72, 

 1847 (no description). 



Astaeus bicarinatus Erichson, Arch. f. Naturgesch., 12ter Jahrg., I, p. 376, 1846 

 (after Gray). 



